Hanger assembly improvement



June 21, 1966 J. D. WATTS ETAL 3,257,130

HANGER ASSEMBLY IMPROVEMENT Filed Oct. 26, 1960 2 Sheets-Sheet 1INVENTORS JOHN D. Wms

ELwooD k. Dwcaflk ATTORNEYS June 21, 1966 J. D. WATTS ETAL 3,257,130

HANGER ASSEMBLY IMPROVEMENT Filed Oct. 26. 1960 2 Sheets-Sheet 2 Fig.2

I06 IOO/ 7 INVENTOR-S JOHN D. WATTS ELwooD k. PIEQQEJE.

ATTORNEYS United States Patent Filed Oct. 26, 1960, Ser. No. 65,064 2Claims. (Cl. 285147) This invention relates to well completion equipmentand more particularly to apparatus for effecting a permanent sealbetween a casing head and a tubing head and the exterior periphery of'atubing string suspended in the casing head.

The invention may be employed in building safe oil wells by the methodsdescribed in US. Patents 2,117,444 issued May 17, 1938 and 2,082,413issued June 1, 1937, to Mueller and Yancey. The description ofapplicable structure and steps in operation which appear in thesepatents is not repeated in detail herein, it being understood that theyare referred to as showing equipment and methods which would be usedwith the present invention and to that extent they form a part of thepresent disclosure.

The use of slip type hanger assemblies to suspend a tubing string withina casing head is well-known. In the normal operation of such hangerassemblies, the tubing string is gripped by the slip segments of thehanger assembly at a position spaced below the upper end of the tubingstring, the latter extending upwardly from the hanger assembly above thecasing head within which the hanger assembly is landed. In mostinstances, the hanger assembly is provided with atemporary sealing meanswhich is operable to-effect a pressure-tight seal between the innerperiphery of the casing head bore and the outer periphery of the tubingstring. There have been many proposals for effecting a permanent sealbetween the easin'g head bore, the tubing head bore mounted on thecasing head and the exterior periphery of the upwardly extending end ofthe tubing string. For example, in some installations the hangerassembly itself has an upper extension which engages within the lowerend of the tubing head bore and is arranged to be permanently sealed tothe upper end of the tubing string. It has also been proposed toconstruct the hanger assembly of two sections, the lower section ofwhich is utilized to land the tubing string within the casing head andprovide a temporary seal while the upper section is arranged to effectthe permanent seal being the casing head bore, tubing head bore andtubing string.

l An object of the present invention is the provision of apparatus ofthe type described including a casing head, ahangar assembly forsuspending a tubing string within the casing head, a tubing head mountedon the casing head and an improved annular member arranged to be mountedbetween the casing head bore and the tubing head bore independent of thehanger assembly for providing a permanent seal between the latter andthe exterior periphery of the upwardly'extending end of the tubingstring. 1

Another object of the present invention is the provision of an apparatusof the type described having improved means for effecting a permanentseal between the casing head bore, a tubing head bore and the exteriorperiphery of a tubing string supported in the casing head.

Still another object of the present invention is the provision ofapparatus of the type described which is simple in construction,efficient in operation, and economical to manufacture and maintain.

These and other objects of the present invention will become moreapparent during the course of the following detailed description andappended claims.

ice

The invention may best be understood with reference to the accompanyingdrawingswherein illustrative embodiments are shown.

In the drawings:

FIGURE 1 is a vertical sectional view of a casing head 7 I having atubing head mounted thereon showing a hanger assembly, in elevation withparts broken away, landedin the casing head and supporting a tubingstring and an annular member, in elevation with parts broken away,providing a permanent seal between the well heads and the tubing string,such apparatus embodying the principles of the present invention; and

FIGURE 2 is an enlarged, fragmentary, vertical crosssectional view ofthe apparatus shown in FIGURE 1 illustrating an annular sealing memberof a modified form.

Referring now more particularly to FIGURE 1, there i is shown thereinwell head apparatus embodying the principles of the present invention,which includes a casing head 10 which is utilized in the well in theusual manner and has connected therewith a casing pipe 12 ofconventional construction. The well head 10 is provided with a throughhere 14, the lower end of which is threaded to receive the upper end ofthe casing pipe 12 and the central portion of which communicates withthe usual radially extending lateral flow openings 16. The upper end ofthe casing head bore 14 has a first counter-bore 18 formed therein whichdefines with the bore 14, an

annular shoulder 20 providing an upwardly facing annular seat forreceiving and supporting a hanger assembly, generally indicated at 22.The hanger assembly is arranged to engage and support a tubing string 24within the casing head 10 with the upper end portion of the tubingstring extending above the hanger assembly and the casing head 10. t

The well head apparatus of the present invention also includes a tubinghead 26 having a through bore 28 formed therein, the lower end of whichis provided with a downwardly facing frusto-conical seating surface 30.The casing head bore 14 is formed with a second counterbore 32 adjacentthe upper end thereof which forms with the counterbore 18 an upperannual seat 34. Mounted between the seats 30 and 34 is an annularsealing element or member 36 having an upwardly facing frusto-conicalsurface 38 formed on the upper periphery thereof for engaging thedownwardly facing frusto-conical surface 30 and an annular shoulder orseat 40 formed on the lower periphery thereof for engaging the annularseat 34. Preferably, a sealing ring 41 is mounted within a suitableannular groove formed in the surface 30.

Any suitable means may be employed for mounting the tubing head 26 onthe casing head -10, and, as shown, the casing head 10 includes an upperannular flange 42 and the tubing head '26 is provided with a generallycorresponding lower annular flange '44, the flanges being suitablyapertur'ed at circumferentially spaced positions to receive conventionalbolt assemblies 46 which may be tightened to secure the two flangestogether. Preferably, an annular sealing ring 48 is provided between theflanges 42 and 44 of the Well heads adjacent their inner peripheries.The annular sealing element 48 is preferably of the type disclosed inWatts et al. Patent 2,766,829, and includes a generally flat ringarranged to be disposed between the opposed horizontal surfaces of theflanges 42 and 44 and having lips 50 extending from the inner endthereof. The lips 50 provide exterior frusto-conical surfaces forengaging frusto-conical surfaces 52 and 54 formed in the bores of theheads 10 and 26 respectively. It will be understood that the sealingelement 48 is of metal and the frusto-conical surfaces of the lips 50have an angle somewhat steeper than the frusto-conical surfaces 52 and54, these surfaces being brought into par- 3 allelism when the boltassemblies 46 are tightened, thus providing an effective seal betweenthe bores of the heads and 26.

While the hanger assembly 22 may be of any suitable construction whichpreferably embodies slip segments for engaging and supporting the tubingstring, there is shown in the drawings a slip type hanger assembly whichis also of the wrap around type such as disclosed in our co-pendingapplication Serial No. 798,708, filed March 11, 1959, now Patent No.3,051,513. Thehanger assembly 22 includes a pair of upper arcuatesegmental members 56 of semicircular configuration, which members, whendisposed in cooperating relation with respect to each other, form a slipbowl providing an exterior cylindrical surface arranged to closely fitwithin the counterbore 18 of the casing head 10. The interior surface ofthe segmental members 56 are provided with a series of vertically spaceddownwardly and inwardly inclined frustoconical surfaces 58. Disposedwithin the slip bowl formed by the segmental members 56 is a plulowersegmental member on opposite sides of the tongue rality of segmentalslips 60, each having a series of vertically-spaced exteriorfrusto-conical wedging surfaces 62 engageable with the surfaces 58. Eachsegmental slip also includes an interior serrated surface 64 ofgenerally arcuate configuration for engaging the exterior surface of thetubing string 24 to support the latter.

As shown in FIGURE 1, there are four segmental slip-s provided, eachsegmental member 56 having a pair of slips associated therewith. Inorder to maintain the proper relation between the slips so that inoperation they will move radially inwardly in response to downwardmovement relative to the members 56, each slip has a pin 66 extendingtangentially from one longitudinal edge thereof and the oppositelongitudinal edge has a tangentially extending bore 68 formed thereinfor receiving the pin 66 of the adjacent slip. It will be understoodthat suitable means (not shown) is provided for selectively maintainingthe slips in their upper position with respect to the members 56 so thatthe slips can be properly assembled and then released for operativeengagement with the tubing string.

- The hanger assembly 22 also includes a pair of lower segmental members70 which, when positioned in cooperating relation, form a compressionring having a downwardly facing frusto-conical surface 72 providing aseat for engaging the seat 20 of the casing head 18. Each of the lowersegmental members 70 is connected with a corresponding upper segmentalmember 56 for relative a-rcuate movement with respect thereto so thatwhen each cooperating pair of upper and lower segmental members is inco-extensive alignment, the hanger assembly can be separated for removalor mounting around the tubing string 24 between the ends thereof andthen secured in position therearound by effecting a relative arcuatemovement between the lower members and upper members during which theseparation between the lower members and upper members are bridged bythe respective upper and lower members.

To this end, the lower portion of each upper segmental member 56 hasformed therein an upwardly extending ancuate slot 74 of generallyinverted L-shaped configuration to receive an arcuate tongue 76extending upwardly from the associated lower segmental member 70, thetongue being of corresponding general inverted L-shaped configuration.The tongue and groove connection 74 and '76 provided between the upperand lower segmental members serves to afford radial rigidity to themembers when in operative position and yet provide a limited amount ofrelative vertical movement therebetween. This relative vertical movementis provided in order to compress a sealing means, generally indicated at78, which is mounted between the upper and lower members.

The sealing means comprises a segmental sealing ring 80 having inner andm ter portions mounted on each 76, one end of the inner and outersealing ring portions 60 being interconnected by an integral portionproviding a tongue 82 and the opposite ends thereof being interconnectedby an integral portion providing a corresponding groove 84.

It will be seen that during the landing of the hanger assembly 22, seat72 thereof will engage seat 28 of the casing head and slip-s 60 willmove downwardly within the slip bowl thus effecting radial movement ofthe serrated surfaces 64 thereof into supporting engagement withtheperiphery of the tubing string 24. As the weight of the tubing stringis transferred to the seat 72, sealing ning will be compressedrespectively into engagement with the counterbore 18 and exteriorperiphery of the tubing string 24 to provide a temporary sealtherebetween.

The annular member 36 is formed with a through bore 86 for receiving theupper end of the tubing string 24 and means is provided in the bore 86for effecting a permanent seal between the annular member 36 and theexterior periphery of the tubing string. As shown in FIGURE 1, thepermanent sealing means of the annular member 36 is in the form ofwelding material 88 deposited between the upper extremity of the tubingstring and an annular groove 90 formed in the upper extremity of thebore 86. In order to test the effectiveness of the seal provided by thewelding material 88, a resilient annular sealing ring 92 is mountedwithin a suitable groove formed in the bore 86 in a position spacedbelow the groove 90. A radially extending test port 94 is formed in theannular member between the resilient sealing element 92 and the bore 90.In accordance with the usual practice, after the welding material 88 hasbeen deposited between the annular member 36 and tubing string 24, testpressure is applied through the test port 94 to deter mine theeffectiveness of the weld, the resilient sealing ring 92 serving to holdsuch test pressure against leakage in the opposite direction.

Referring now more particularly to FIGURE 2, there is shown therein anannular member 96 which may be utilized in place of the annular member36 previously described. The annular member 96 has its upper outerperiphery provided with a frusto-conical seating surface 98 for engagingthe frusto-conical surface 30 of the tubing head. The lower exteriorperiphery of the annular member 96 is formed with a downwardly facingfrustoconical seating surface 100 which is arranged to engage anupwardly facing frusto-conical seating surface 102 formed in the casinghead'counterbore 18 in lieu of the shoulder 34 previously described.Both the seating surface 98 and the seating surface 100 are preferablyprovided with sealing elements 184 and 106 respectively, which aremounted within appropriate grooves formed in the respective surfaces.

FIGURE 2 also illustrates a seal between the flanges 42 and 44 of theheads 10 and 26 in the form of an API ring 168 which is engaged withinan annular groove formed in the opposed surfaces of the flanges. The APIring may be used in lieu of vthe sealing ring 48 described in connectionwith the embodiment shown in FIGURE 1. The annular member 96 is providedwith a permanent sealing means for engaging the exterior periphery ofthe tubing string which is utilized in lieu of the welding material 88previously described. As shown, the annular member 96 is formed with abore 110 to receive the tubing string and a counterbore 112 is formed inthe upper portion of the bore 110. Mounted in the bottom of thecounterbore is an annular packing end ring 114 having annular packing116 engaged thereagainst. Mounted within the counterbore and inengagement with the packing 116 is a packing spacer ring 118 which alsoengages at its upper end packing 120. The packing 120 is engaged by anupper packing end ring 122 which, in turn, is engaged by a packing glandsleeve 124 threadedly mounted within the upper end of the counterbore112. It will be seen that by turning the packing gland sleeve 124 withinthe counterbore, packing 116 and 122 will be compressed into sealingengagement between the packing end rings and the packing spacer ring andinto pressure-tight engagement with the counterbore 112 and adjacentperiphery of the tubing string. The packing spacer ring 118 is providedwith an opening through which test pressure may be applied through atest port 128 to insure the eflz'ectiveness of the seal provided by thepacking 116 and 122.

In a like manner, in order to insure that the seal between the bores ofthe heads and 26 is effective, there is provided a test port 130 whichextends through the flange 42 of the casing head and communicates withthe horizontal surface thereof at a position spaced inwardly from theAPI ring 108. After the two heads have been secured together, testpressure may be applied to the test port 130 to test the effectivenessof the seal between the inner engaging sealing surfaces 30 and 98, 100and 102, and the effectiveness of the seal provided by the API ring,108.

It will be understood that in the embodiment shown in FIGURE 2 theloading from the upper to the lower head is carried by the member 96 andthe API ring 108. In some installations it is possible to eliminate theAPI ring 108 and thus eliminate the necessity of the grooves in theflanges of the upper and lower heads as well as the test port 130. Inthis arrangement the annular member 96 serves as the sole means fortransmitting the load between the upper and lower heads. It will benoted, however, that the load of the casing is supported independentlyof the annular member.

It thus Will be seen that the objects of this invention have been fullyand effectively accomplished. It will be realized, however, that theforegoing specific embodiment has been shown and described only for thepurpose-of illustrating the principles of this invention and is subjectto extensive change without departure from such principles. Therefore,this invention includes all modifications encompassed within the spiritand scope of the folon said first conduit head, means defining alignedthrough bores in said first and second conduit heads, a hanger assemblysupported in the through bore of said first conduit head, a string ofwell conduit supported by said hanger assembly with its upper endextending into the lower end of the through bore of said second conduithead, and an annular member separate from said hanger assembly, saidannular member supported solely on said first conduit head within saidfirst head through bore, said annular member extending within both ofsaid through bores and sealingly engaging the interior surface of eachthrough bore, said annular member also sealingly engaging the outersurface of said well conduit adjacent the upper end of said conduit.

2. The combination as set forth in claim 1 wherein said hanger assemblycomprises a plurality of complementary segmental members each having atleast one upper segmental element interengaging a lower segmentalelement, said upper and lower elements being arcuately movable withrespect to one another between a first position wherein the upper andlower segmental elements on each segmental member are substantiallycoextensive and said complementary segmental members are separable fromone another and a second position wherein at least one upper segmentalelement and lower segmental element on each segmental member interengageand arcuately extend with at least one upper segmental element and lowersegmental element of each adjacent complementary segmental member, sothat said hanger assembly comprises a radially rigid unit when saidelements are disposed in said second position.

References Cited by the Examiner UNITED STATES PATENTS 2,097,615 11/1937Burns 285-144 2,313,169 3/1943 Penick et al. 285-133 I 2,402,723 6/1946Bean 285-144 2,485,497 10/1949 Lemley 285-444 2,491,598 12/1949 Allen285-343 3,051,513 8/1962 Watts 285146 CARL w. TOMLIN, PrirrtaryExaminer.

R. L. MCLEAR, R. V. PARKER, JR., S. R. MILLER,

D, W. AROLA, Assistant Examiners,

1. IN A WELL HEAD ASSEMBLY, THE COMBINATION COMPRISING: A FIRST CONDUITHEAD, A SECOND CONDUIT HEAD MOUNTED ON SAID FIRST CONDUIT HEAD, MEANSDEFINING ALIGNED THROUGH BORES IN SAID FIRST AND SECOND CONDUIT HEADS, AHANGER ASSEMBLY SUPPORTED IN THE THOUGH BORE OF SAID FIRST CONDUIT HEAD,A STRING OF WELL CONDUIT SUPPORTED BY SAID HANGER ASSEMBLY WITH ITSUPPER END EXTENDING INTO THE LOWER END OF THE THROUGH BORE OF SAIDSECOND CONDUIT HEAD, AND AN ANNULAR MEMBER SEPARATE FROM SAID HANGERASSEMBLY, SAID ANNULAR MEMBER SUPPORTED SOLELY ON SAID FIRST CONDUITHEAD WITHIN SAID FIRST HEAD THROUGH BORE, SAID ANNULAR MEMBER EXTENDINGWITHIN BOTH OF SAID THROUGH BORES AND SEALINGLY ENGAGING THE INTERIORSURFACE OF EACH THROUGH BORE, SAID ANNULAR MEMBER ALSO SEALINGLYENGAGING THE OUTER SURFACE OF SAID WELL CONDUIT ADJACENT THE UPPER ENDOF SAID CONDUIT.